1. Field of the Invention
The present invention relates to a liquid ejection apparatus and a liquid ejection method using the liquid ejection apparatus. More particularly, the invention relates to a liquid ejection apparatus and a liquid ejection method for ejecting liquid inside a tank into a space above the liquid surface, or towards a peripheral wall.
2. Description of the Related Art
In fermentation and culturing, the fermenting liquids and culturing liquids are very prone to foaming. Due to agitation during the process, there is a considerable amount of foaming so that operability is often impaired. In order to inhibit such foaming, and to disperse the temporarily created foam, anti-foaming agents such as silicone are added. The addition of such anti-foaming agents however not only involves significant cost, but also poses a risk adversely affecting the fermentation and culturing processes, because these anti-foaming agents are in themselves foreign substances to the liquids. In addition, the anti-foaming agents are mixed with the product as impurities so that the quality of the product is degraded. Moreover additional time is required to remove them from the product. Furthermore they are mixed in the waste liquid and thus impede the treatment of the waste liquid. Hence the addition of anti-foaming agents is an undesirable means, which should be avoided as much as possible.
A problem is that the inner peripheral surface of the wall of the agitating tank becomes contaminated by micro-organisms or solid raw materials or products being deposited thereon. This often causes a decrease in reaction yield or a reduction in heat transfer coefficient of the agitating tank peripheral wall. In this case, it is practically impossible to wash the inner peripheral surface of the wall of the agitating tank to remove the extraneous matter from the inner peripheral surface of the agitating tank without stopping the operation in the agitating tank.
Yet another problem is that when apparatus such as jackets, and coiled pipes and multi-tube heating units are respectively provided on the outer peripheral surface of the peripheral wall of the agitating tank and inside the agitating tank, as apparatus for heating or cooling the liquid inside the agitating tank, there is often the situation where the liquid inside the agitating tank decreases due for example to evaporation so that with time, the liquid level inside the agitating tank drops, and the heat transfer area of the heating or cooling apparatus cannot be effectively utilized.
In order to increase and hence recover the reduced heat transfer area, there is a means involving supplying fresh liquid to the tank so that the liquid surface is raised; and a method involving circulating the remaining liquid inside the tank by means of a pump provided outside the tank to distribute the liquid onto the inner peripheral surface of the tank wall. The former wherein fresh liquid is supplied to the tank, has the defect that there is an abrupt change in the composition of the liquid inside the tank, requiring a change in operational conditions, and also the quality of the product changes. Moreover, the latter has the defect that it requires a pump and piping for circulating the remaining liquid, so that after operation, residual liquid remains in the tank as well as inside the piping.
Accordingly, means which can be put into practice to solve the defect that the heat transfer area cannot be effectively used have yet to be found.
When desired to evaporate the liquid inside the agitating tank, there is a method involving immersing a heating device in the liquid and/or mounting a heating device on the outside of the agitating tank peripheral wall, to thereby apply heat to cause evaporation from the liquid surface either while agitating or not agitating the liquid. With this method there is the defect that the heat in the space above the liquid surface which is heated by the heating device cannot be effectively utilized, and that the heating of the liquid is limited to the contact area of the heating device, so that the heat from the heating device cannot be effectively utilized and the rate of evaporation of the liquid is slow.
The present inventors have overcome the defects with the conventional agitation such as contamination of the surface of the inner peripheral surface of the peripheral wall of the agitating tank and the surface of the heating or cooling apparatus and a reduction in the heat transfer area by using only mechanical agitation. Hence, with good efficiency, the inner peripheral surface of the peripheral wall of the agitating tank and the surface of the heating or cooling apparatus are washed, thereby preventing the reduction in the heat transfer area of the inner peripheral surface of the peripheral wall of the agitating tank and of the heating or cooling apparatus. Moreover, the accumulated results of a thorough study into agitating blades and agitating methods which can achieve mixing of liquids of different specific gravities and suspensions with good efficiency, have led to an invention related to agitating blades and agitating methods (EP 0619136A).
The agitating blades of this prior invention are agitating blades wherein a liquid transporting body such as one or a plurality of tubular bodies, gutter bodies, and plates, is attached preferably at an incline to an attachment device mounted on an agitator shaft, the liquid transporting body being open at both ends with an upper opening and lower opening.
The present inventors, from the accumulated results of continuous investigations to solve the former problems discovered the following problems in the invention related to the beforementioned patent application. That is to say, in the abovementioned prior application, the liquid transporting body is preferably secured at an incline. Since the inclination angle is fixed and is not changed, then in changing the purpose of use and the conditions of the agitating blades, the agitating blades must be stopped and removed from the tank to change the inclination angle.
Furthermore, with the tubular body constituting the liquid transporting body, normally it is common for this to be in contact with liquids with strong corrosive characteristics. Hence in order to have complete corrosion resistance, the surface is coated or lined with a substance having a high corrosion resistance such as a synthetic resin like polytetrafluoroethylene, or glass or a ceramic or the like. However, while with such a coating or lining, the technology has improved remarkably, there is still the danger of pinholes. Consequently due to these pinholes, it is difficult to ensure the reliability of the corrosion resistance of the coated or lined tubular body.
In order to increase the reliability of the corrosion resistance of the tubular body, then prior to use of the tubular body, the presence of pinholes in the coating layer or the lining layer of the tubular body (these layers are in general referred to simply as a lining layers) is preferably checked for not only on the outer face of the pipe but also on the inner face. However, checking for the presence of pinholes in the inner face of the pipe is extremely difficult, Moreover, even if pinholes are found, it is difficult to repair these pinholes.
Therefore it is preferable to use a gutter body as the liquid transporting body, since with a gutter body, it is easy to check for the presence of pinholes in the lining layer, and hence to repair the pinholes.
In the specification of the beforementioned prior patent application, in the case where a gutter body is used as the liquid transporting body, the principle of raising the liquid with the gutter body and discharging this from the upper opening is disclosed. However there is no disclosure at all regarding the mounting face and the mounting direction.
With regards to use, in the case where the liquid discharged from the upper opening of the gutter body is used for example for washing the inner peripheral surface of the tank wall by distributing this onto the inner peripheral surface of the tank wall, or for maintaining the heat transfer area and/or washing the heat transfer surface by distributing this onto the heat transfer surface, or for evaporation by distributing this into the space above the liquid surface, then needless to say it is preferable to have a large distance and quantity (hereunder referred to as the ejection distance and ejection quantity) for the liquid ejected from the upper opening of the liquid transporting body.
It is an object of the present invention to take into consideration the above situation with conventional liquid ejection apparatus and provide an improved liquid ejection apparatus and improved liquid ejection method using the liquid ejection apparatus.
The present inventors selected the size of the inclination angle of the liquid transporting body in order to increase the ejection distance and ejection quantity of the ejected liquid. Furthermore, in the case where the liquid transporting body was a gutter body, it was realized that the mounting face and mounting direction of the gutter body must be selected for the ejection distance and ejection quantity of the liquid from the upper opening of the gutter body. The present invention has been reached based on this knowledge.
According to a first aspect of the invention there is provided a liquid ejection apparatus wherein at least one gutter body serving as a liquid transporting device and having a lower opening and an upper opening at respective lower and upper end portions thereof is secured to an agitator shaft by means of an attachment device, the gutter body having an inclination angle greater than 0xc2x0 and up to 90xc2x0, and the gutter body is revolved around the agitator shaft axis with a concavity facing the agitator shaft or the revolution direction, and the lower opening of the gutter body immersed beneath a liquid surface, and the upper opening of the gutter body exposed from the liquid surface, so that the liquid at the immersed portion of the gutter body passes within the gutter body and is ejected from the upper opening thereof.
According to a second aspect of the invention there is provided a liquid ejection apparatus wherein at least one gutter body serving as a liquid transporting device and having a lower opening and an upper opening at respective lower and upper end portions thereof is mounted on an agitator shaft by means of an attachment device, the gutter body having an inclination angle which is adjustable to be greater than 0xc2x0 and up to 90xc2x0, and the gutter body is revolved around the agitator shaft with a concavity facing the agitator shaft or the revolution direction, and the lower opening of the gutter body immersed beneath a liquid surface, and the upper opening of the gutter body exposed from the liquid surface, so that the liquid at the immersed portion of the gutter body passes within the gutter body and is ejected from the upper opening thereof.
According to a third aspect of the invention there is provided a liquid ejection apparatus wherein at least one tubular body serving as a liquid transporting body and having a lower opening and an upper opening at respective lower and upper end portions thereof is mounted on an agitator shaft by means of an attachment device, the tubular body having an inclination angle which is adjustable to be greater than 0xc2x0 and up to 90xc2x0, and the tubular body is revolved around the agitator shaft with the lower opening of the tubular body immersed beneath a liquid surface, and the upper body opening of the tubular body exposed from the liquid surface, so that the liquid at the immersed portion of the tubular body passes within the tubular body and is ejected from the upper opening thereof.
According to a fourth aspect of the invention there is provided a method of ejecting a liquid involving revolving the liquid transporting body of the liquid ejection apparatus according to the abovementioned respective first, second and third aspects of the invention, around the agitator shaft with the lower opening immersed beneath the liquid surface, and the upper opening exposed from the liquid surface, so that the liquid at the immersed portion of the liquid transporting device passes within the liquid transporting device and is ejected from the upper opening thereof.
The liquid ejected from the upper opening of the liquid transporting device in the fourth aspect of the invention is used for example for washing the inner peripheral surface of a container wall, for maintaining the heat transfer area and/or washing the heat transfer surface, or for evaporating the liquid in the space above the liquid surface.
With the present invention while having no particular limit, the terms upper and lower are respectively defined as a position near to the bottom of the liquid and a position far from the bottom of the liquid.
The attachment device is for mounting one or more liquid transporting bodies on the agitator shaft. The attachment device may be a rod, a rectangular or square bar, a shaped steel body, a pierced plate body (referred to hereunder as a perforated plate), or a non-perforated plate. With the non-perforated plate and perforated plate, these are preferably attached to the agitator shaft such that when turned within a liquid, the fluid resistance is as small as possible. When the non-perforated plate is used vertically in the liquid (perpendicular to the rotation plane of the liquid transporting body) the width is preferably narrow.
The rods, square bars, shaped steel bodies, perforated plates and non-perforated plates are positioned approximately on a radius or diameter in the revolution plane. The number of rods, square bars, shaped steel bodies, perforated plates and non-perforated plates may be one or more. When a plurality are used, then normally each member is positioned either on the same revolution plane or on planes differing from each other.
One or a plurality of liquid transporting bodies may be attached to one attachment device. The number of liquid transporting bodies attached to one attachment device is appropriately selected depending for example on the viscosity of liquid, the type of liquid transporting body, the thickness of the liquid transporting body, the diameter of the container itself, the angle between the agitator shaft and the liquid transporting body, and the use of the liquid ejected from the upper opening of the liquid transporting body (referred to hereunder as the ejected liquid). So are when the attachment position of a liquid transporting body is decided in the case when one liquid transporting body is attached to one attachment device, or when the spacing and the attachment position of the neighbouring liquid transporting bodies are decided in the case where a plurality of the liquid transporting bodies are attached to one attachment device.
The gutter body serving as the liquid transporting body is preferably made from a metal such as steel or stainless steel with the surface coated or lined with a substance having a high corrosion resistance such as a synthetic resin like polytetrafluoroethylene, or glass or a ceramic or the like. However this may be made from a corrosion resistant material such as highly corrosion resistant plastics or metal, or glass or ceramics.
The gutter body is a long body having an opening in a longitudinal direction. The shape of the central transverse section, and the respective shapes of the upper end opening and lower end opening of the gutter body have no particular limitation. It is also possible to make these a left/right symmetrical or a left/right non-symmetrical shape (referred to hereunder as symmetrical shape and non-symmetrical shape). However in practice the former is preferable.
As a representative example of the symmetrical shape, the following can be considered; a circumference with part of an arc missing (referred to hereunder as a cut out circumference), a semi-circle, a semi-elliptical circumference, a half oval, a U-shape, a V-shape, polygon shapes such as; a trapezoid, a square, a rectangle, a modified pentagon shape wherein a right octagon shape has been divided in two by a straight line connecting a first point and a fifth point thereof, and a modified hexagon shape where a right octagon shape has been divided in two by a straight line connecting the central points of respective first and fifth sides thereof, as well as shapes wherein the head angles of the polygon shapes are rounded and/or the sides are bent outwards with a small curvature (referred to hereunder as substantially polygon shapes) and one side is removed.
As a representative example of the non-symmetrical shape, there are for example shapes where one of the peripheries or the sides at the edge (referred to hereunder as the opening edge) corresponding to the two peripheral edges of the opening of the beforementioned symmetrical shapes is extended (these symmetrical shapes and non-symmetrical shapes are referred to hereunder as open shapes).
The gutter body may be made of an equal sided V-shaped steel body, an H-shaped steel body, or as a C-shaped steel body wherein the transverse section is a quadrilateral of square or rectangular shape or is circular. The C-shaped steel body is preferable. The equal sided V-shaped steel body gives a gutter body having a right angled V-shape opening. The H-shaped steel body gives a gutter body having a square or rectangular shaped opening with respective opposite sides missing. The C-shaped body wherein the transverse section shape is a quadrilateral gives a gutter body having a quadrilateral shape opening with one portion of one side missing, while the C-shaped steel body wherein the transverse section is circular gives a gutter body having a cut-out circumference opening.
In coating or lining the gutter body which in itself is known, prior to coating or lining, the edges of the openings are preferably rounded, or enlarged into a column shape.
The shape and size of the respective upper and lower openings of the gutter body can be the same as each other or different from each other.
Preferably the area of the upper opening is smaller than the area of the lower opening. The respective opening areas of the upper opening and the lower opening of the gutter body are defined as the areas which acquire the through flow of liquid along the concavity of the gutter body. With the respective opening areas of the upper opening and lower opening of the gutter body, in the case where the shape of the upper opening and lower opening are an open shape with left-right symmetry, then this is the area enclosed by the shape and a straight line connecting the opposite opening edges. In the case where the transverse section shape of the upper opening and lower opening is a non-symmetrical open shape, then this is the area enclosed by the shape and a straight line connecting the extended portion edge and the other opening edge, or the area enclosed by the shape and a straight line connecting the opposite opening edges excluding the extended portion.
There is no particular restriction on the shape of the side face of the gutter body (referred to hereunder as the side shape), however normally this is a straight line, a curve which is bent at a small curvature so as to protrude upward or downward, or an S-shape wherein the upper end and/or the lower end of a straight line or the beforementioned curve are further extended in the transverse direction. For the curve, a parabola is preferably. Among other things, a straight line is preferably since this simplifies formation of the gutter body. Moreover, a curve which is bent so as to protrude downwards is preferably since this enables an increase in the discharge distance and/or the discharge amount. A parabola which is bent so as to protrude downwards is particularly desirable.
There is no particular restriction on the shape as seen from the front (referred to hereunder as the front shape), however normally this is a straight line, a curve which is bent at a small curvature in the transverse direction (a direction parallel with the rotation plane of the gutter body; defined similarly hereunder), or an S-shape wherein the upper end and/or the lower end of a straight line or the beforementioned curve are further extended in the transverse direction. However, a straight line is preferable.
As with the beforementioned side shape and front shape, there is no particular restriction on the shape as seen from above or beneath (referred to hereunder as the plan shape). This may be a straight line, a curve which is bent at a small curvature towards the direction of revolution of the gutter body or the opposite direction, or an S-shape wherein the upper end and/or the lower end of a straight line or the beforementioned curve are further extended in the transverse direction. However among other things a straight line is preferable.
There is no particular limit to the length of the gutter body. The lengths of a plurality of gutter bodies attached to the attachment device can be the same as each other, or may be different from each other.
The gutter body may be twisted sufficiently to obtain raising of the liquid.
The gutter body is attached to the agitator shaft with the concavity facing the agitator shaft or the revolution direction. In this case, the eccentric or deviation angle defined hereinunder is appropriately selected depending for example on the shape of the gutter body itself and the opening shape, the opening area ratio between the upper and lower openings, and the use of ejected liquid. The eccentric or deviation angle means angle between the center line of the gutter body (being the line perpendicular to and equally dividing a line connecting the symmetrical shape opposite edges of the opening; defined similarly hereunder) and a diameter of the revolution plane of the gutter body which passes through the center point of the gutter body (the intersection point of the before-mentioned center line of the gutter body and gutter body; defined similarly hereunder).
In order to eject the liquid from the upper opening of the gutter body as a spray, as minute droplets, or as a fine flow, then the whole of the upper opening of the gutter body can be covered with a perforated plate drilled with a plurality of holes, or with a mesh. This is also preferable. With the perforated plate, the plurality of holes may be pierced regularly or irregularly. There is no particular restriction on the shape and number of holes. As a representative example of the shape of the holes, these may be circular, elliptical, square or rectangular.
A deflector plate may be provided spaced apart from the upper opening of the gutter body, to thereby abruptly change the direction of the liquid ejected therefrom. Moreover, with the gutter body, the upper opening may be closed off by a plate such that a gap is formed along the inner peripheral surface of the gutter body.
The longitudinal opening of the gutter body may be covered with a non-permeable or permeable cover which is removable.
Moreover, the gutter body may be free to turn around the longitudinal axis thereof. In this case, the eccentric or deviation angle is appropriately selected depending for example on the shape of the opening and the size of the inclination angle of the gutter body, the viscosity of the liquid in the container, and the revolution speed of the gutter body. In the case when the gutter body is free to turn around longitudinal axis thereof as mentioned above, the gutter body may be rotatably mounted on the attachment device. In this case the gutter body may also be secured after being turned to an optical eccentric or deviation angle. Moreover, this can be turned automatically depending on the revolution speed of the gutter body. In this case, the gutter body is mounted on the agitator shaft so as to be freely rotatable.
When attaching the gutter body to the attachment device, the arrangement must be such that the attachment device does not obstruct the rising of the liquid within the concavity of the gutter body.
The gutter body is secured to the attachment device at an inclination angle of a predetermined size. Furthermore, this may be mounted such that the size of the inclination angle (the angle between the longitudinal axis of the gutter body and the rotation plane of the gutter body: defined similarly hereunder) can be optionally adjusted. The latter arrangement however is preferable. Here the longitudinal axis of the gutter body is defined as the line connecting the center points of the gutter body at the respective upper and lower openings.
The inclination angle is made greater than 0xc2x0 and up to 90xc2x0. The lower opening may be closer to the agitator shaft than the upper opening, or the distances from the agitator shaft to the lower opening and to the upper opening may be made equal to each other. In practice however, the former is desirable. In the case of the latter, then the lower opening of the gutter body is preferably closed off. In this case also, the liquid at the immersed portion of the gutter body is raised inside the gutter body. The size of the inclination angle is appropriately selected depending for example on the type of liquid, the rotational speed of the liquid transporting body, the desired discharge distance and discharge amount for the ejected liquid, and the use of the ejected liquid. Normally 5xc2x0 to 85xc2x0 is ideal.
The size of the inclination angle of a gutter body is appropriately selected depending for example on the shape of the gutter body itself and the opening shape, the opening area ratio between the upper and the lower openings, and the use of the ejected liquid.
In order to mount the gutter body on the agitator shaft so that the size of the inclination angle can be adjusted, then for example the lower end portion of the gutter body may be hinged so as to fit over the agitator shaft, and the upper end mounted so that the upper opening of the gutter body is movable along the radius of the rotation plane by means of a vertical traveller device or a horizontal traveller device. The device for moving the upper opening of the gutter pipe involving a vertical traveller device, and the device involving a horizontal traveller device are referred to hereunder respectively as a vertical system and a horizontal system.
Furthermore, the gutter body may be bendable and/or able to be telescoped. To make the gutter body bendable, then for example the gutter body may be made from a flexible material, or the gutter body may be divided into a plurality of sections, and these sections connected by joint members (a gutter body section is referred to hereunder as a gutter segment). In order to enable telescoping of the gutter body, then for example a plurality of gutter segment may be connected together so as to be slidable relative to each other.
In the case where a plurality of the gutter bodies are secured to an attachment device, then these may be arranged independent of each other, or may be formed integral with each other. For the latter, then for example the opposite inclined sides of a trapezoidal plate may be bent in opposite directions to each other to thereby give gutter bodies formed by the bent portions. In this case, the unbent flat portion may be made the attachment device, or a separate attachment device may be provided for the trapezoidal plate. The unbent flat portion acts as an agitator blade. With this gutter body, the respective shapes of the upper opening and lower opening are non-symmetrical. Moreover, by forming openings in the flat portion constituting the attachment device, then fluid resistance of the attachment device can be reduced. This is also desirable.
When the gutter body is attached so that the lower opening thereof is closer to the agitator shaft than the upper opening thereof, as mentioned hereinunder referring to FIG. 11, the lower opening 11 of the gutter body 1 may be located on or off a plane involving the agitator shaft 3 and the upper opening 12. In the off case, the gutter body 1 can be managed to revolve so that the lower opening 11 is leading or following, although the former is preferable. When a plurality of gutter bodies are attached at an incline, they may be arranged so that the lower end portions cross over each other in the vicinity of the agitator shaft.
In the case where the corrosiveness of the liquid inside the tank is minimal, then instead of a gutter body mounted such that the size of the inclination angle is optionally adjustable, a tubular body may be similarly mounted.
This tubular body, as with the beforementioned gutter body, is preferably coated or lined. However, a coating or lining is not always necessary.
There is no particular restrictions to the shape of the transverse section in case of the tubular body (the section perpendicular to the longitudinal axis). However, shapes such as circular types including circles, ellipses, or ovals, polygon types including squares, rectangles, pentagons, and hexagons, and shapes wherein the head angles of polygons are rounded and/or the sides are bent outwards with a small curvature (referred to hereunder as substantially polygon shaped) are preferable.
The upper opening and lower opening of the tubular body may constitute respective bases of the tubular body. Furthermore, the tubular body may be formed by covering the bases with base plates and drilling holes in the ends of the tubular body.
The attachment device with the liquid transporting body attached thereto may be secured to the agitator shaft, or slidably mounted thereon, no matter which the transporting body may be, gutter body or tubular body. The lower opening of the liquid transporting body is immersed beneath the liquid surface, while the upper opening is exposed from the liquid surface. By rotating the agitator shaft and hence revolving the liquid transporting body, the liquid at the immersed portion of the liquid transporting body is raised inside the liquid transporting body due to the centrifugal force, and is ejected from the upper opening. Together with this, the liquid is agitated by the portion of the liquid transporting body beneath the liquid surface.
With the liquid ejection apparatus of the present invention, the liquid transporting body is secured to the agitator shaft, or is slidably mounted thereon by means of the attachment device. There is no particular restriction to the securing means and for example an insertion, threading, welding or bonding or the like may be used.
In the case where the attachment device is secured, then one attachment device may be mounted on the agitator shaft, or a plurality of attachment devices may be mounted thereon along the longitudinal axis. In the case of the latter, the liquid will be agitated by the liquid transporting bodies which are immersed beneath the liquid surface, and hence this is preferable. Furthermore, in the case of the latter, the lower opening of a lower stage liquid transporting body are preferably made to overlap each other in the longitudinal axis direction of the agitator shaft.
In the case of mounting so as to be slidable, this may be achieved for example by providing on the surface of the agitator shaft along the longitudinal axis thereof a groove or protuberance or spline, and providing on the attachment device a protuberance or groove or spline which can slidably engage with the groove or protuberance or spline on the agitator shaft.
Furthermore, the attachment device slidably mounted on the agitator shaft may be moved automatically or manually. For example, a floating element may be provided on the attachment device so that this can be floated on the liquid surface and thus moved automatically corresponding to the up and down movement of the liquid level inside the tank. Moreover, this may be moved up and down by remote operation from outside the tank. Furthermore, this may be stopped at a predetermined position. In addition, this may be moved up and down by hand, by suspending the attachment device from a connecting wire outside of the tank, and tensioning and slackening the wire outside of the tank.
The floating element may also serve a dual role as an attachment device. The floating element is preferably of a shape and construction which will result in minimum fluid resistance during agitation.
With the liquid ejection apparatus of the present invention, the immersed portion of the liquid transporting body acts as an agitating blade. However other agitating blades such as turbine blades, propellers, pitched flat vanes, flat vane disc turbines, flat vanes, curved vanes, or Pfaudler-type impellers and Brumagin-type impellers may be combined together with the liquid transporting body.
Moreover, the attachment device itself may act an agitating blade.
There is no particular restriction to the size of the liquid ejection apparatus of the present invention. For example this may be an optional size such as a laboratory type small scale apparatus used for example inside a flask, or a large scale apparatus used for example inside a large size tank at a manufacturing plant of a factory.
The liquid agitating apparatus of the present invention for installing inside a flask is preferably one where the inclination angle is adjustable by the vertical system.
The ejected liquid ejected from the upper opening of the liquid transporting body may be employed for the following various uses. For example:
(a) For distributing liquid onto the inner peripheral surface of a tank wall to wash the inner peripheral surface;
(b) In the situation where the liquid level inside the tank drops, then in the case of a tank provided with a jacket on the outer surface of the tank wall, for distributing liquid onto the inner surface of the tank wall which serves as a heat transfer surface, or with a tank provided with coiled piping or a multi-tube unit inside the tank, for distributing liquid onto the surface of the coiled piping or of the multi-tube unit which serves as a heat transfer surface, to thereby maintain the heat transfer area, and/or wash the surface;
(c) For distributing liquid into the space above the liquid surface to evaporate the liquid; and
(d) For other uses.
In the case where the ejected liquid is used for evaporating liquid in the space above the liquid surface, then one or a plurality of liquid transporting bodies are attached to one attachment device in the radial direction of the revolution plane with the inclination angle selected corresponding to the revolution speed of the liquid transporting body (peripheral speed in the plane of revolution), so that the ejected liquid is rapidly discharged. Normally this is from 15xc2x0 to 85xc2x0.
Furthermore, in order to evenly distribute the ejected liquid onto the liquid surface then preferably a plurality of liquid transporting bodies are attached to one attachment device.
In the case where the ejected liquid is employed to wash the inner peripheral surface of the tank wall and/or maintain the heat transfer area of the tank wall which serves as a heat transfer surface, then at least one liquid transporting body need be provided on one attachment device at the tip end thereof, with the upper opening of the liquid transporting body close to the inner peripheral surface and within the ejection distance of the ejected liquid therefrom.
Furthermore, in the case where this is employed to maintain the heat transfer area and or wash the heat transfer surface of a heating or cooling apparatus such as coiled tubes or a multi-tube unit provided inside the tank, then only one liquid transporting body need be provided on one attachment device with the upper opening of the liquid transporting body close to the heat transfer surface and within the ejection distance of the ejected liquid therefrom.
With the liquid ejection method of the present invention, the revolution speed of the liquid transporting body is appropriately selected depending for example on the liquid type, the shape and thickness of the liquid transporting body, and the use of the ejected liquid.
Other objects and aspects of the present invention will become apparent from the following description of embodiments, given in conjunction with the appending drawings.